1. Field of the Invention
The present invention generally relates to electronic signal and data repeaters and, more particularly, to a repeater to be used in conjunction with ultrawideband technologies.
2. Background Description
In the coming years, ultrawideband (UWB) transmission technologies will dominate high data rate communications in the last 10-1000 meters of wireless/portable access to a telecommunications grid. With the huge data rates and position location capabilities afforded by UWB, offices, homes, and small environments such as doctors offices, vehicles, or small buildings will rely on UWB communication devices for connections between consumer electronic devices and computer devices.
As UWB devices proliferate, it will be possible to provide immense data rates, at burst rates up to 480 Megabits per second and even greater, in order to create a wireless Universal Serial Bus (USB) capability or home/enterprise networking capability. This will allow cameras, cellphones, computers, and computer and home entertainment and video systems to have very good and fast data rate transmissions in small (say 10 to 50 feet or greater) distances. The great data rates of UWB will open up an entire new world of high speed personal area networks which currently does not exist. Companies such as Time Domain, Xtreme Spectrum Inc, Motorola, Intel and Texas Instruments, are likely to be leading manufacturers or developers of products for UWB communications.
In typical doctors offices, homes, apartment buildings, and large warehouses and store rooms, etc, today there are Wireless (WiFi) access points that can be connected to the ethernet backbone in order to provide WLAN access and internet access to computer platforms. The backbone medium is typically Cat-3 or Cat-5 cabling that has 10baseT, 100baseT or 1 GHz ethernet signaling, and higher. In the future, this backbone may be wireless, for example, where cable companies or telephone/wireless/internet service providers may use mesh networks, WiMax, or last mile MIMO modem devices that bring broadband video, audio, and data/internet traffic to homes from lampposts or street corners. Satellite radio and fiber cable are also viable methods of delivering the backbone plant to buildings and cars.
Today, the expense of the WiFi access points is on the order of one to several hundred dollars when the hardware and installation is factored in. These access points provide the ability of multiple WLAN users (typically computer or PDA users) to gain portable access the internet, and hot spots such as those implemented by Schlotzskys Deli and Starbucks are becoming popular throughout the world. However, these WiFi access points are made to allow users to access the internet, which is a different use and approach than is likely to emerge with UWB networks, which connect devices together in close-in networks.
Ultrawideband technologies are about to become mainstream, and are described in US patent application 20030096578, published May 22, 2003, by John McCorkle, et. al. of Xtreme Spectrum, Inc., U.S. Pat. No. 6,505,032 (the patent publication and U.S. patent being herein incorporated by reference), as well as in “Recent Applications of Ultra Wideband Radar and Communications Systems”, by Robert Fonatna of Multispectral Solutions, Inc. The IEEE 802.15.3 standards bodies have been developing Physical (PHY) and MAC layer standards for dynamic channel selection and repeater service for UWB, which falls under the general IEEE 802.15.3 standards body.
As explained in the powerpoint presentation by Nishant Kumar, of Virginia Tech's MPRG, as well as in the IEEE standards proceedings, the IEEE 802.15.3 MAC operation provides for repeater service request and repeater service grant commands. Devices use passive scanning to listen for beacon frames or for any nearby user device. If there are not nearby devices which are radiating, a device may establish its own piconet. There are a number of frame and superframe structures, and subsections which permit various types of access, such as contention based schemes using, for example, carrier sense multiple access (CSMA), as well as guaranteed time slots for asynchronous or isochoronous data streams and management time slots.
While the MAC standard suggests repeater service to be used by IEEE 802.15.3 devices when the links between devices are not satisfactory, these types of links can only be established if there is sufficient time available in the channel seen by one of the devices which is involved in the repeating operation. As proliferation of UWB devices is likely to be rapid, there is likely to be contention such that the current mode of MAC repeater operation, envisioned by the presently proposed 802.15.3 standard, is not adequate to provide one or more of sufficient security, proper traffic filtering, bandwidth provisioning, network management features, or flexibility of networks that can be installed or controlled easily by a consumer. That is to say, the current repeater operation contemplated by 802.15.3 and proposed UWB devices is based on the assumption that a single chip can perform necessary repeater functions, but this functionality alone will not be adequate for the rapid emergence of UWB and the onslaught of wireless data that is certain to occur.
Currently, IEEE 802.15.3a, the Ultrawideband Physical Layer standard committee, is working on creating a standard that may either be Multiband OFDM transmission (MBOA), with 500 MHz channels, or a Direct Sequence Spread Spectrum impulse radio standard that has broader channel bandwidths (UWB Forum). Ratification of one or both of these standards may occur by the end of 2004, as described in a recent paper submitted to High Frequency Electronics, coauthored by the present inventor.
The High-Tech article by Woz Ahmed and Bipin Parmar (the Chilli) provides a glimpse at the various activities in the Ultrawideband standard bodies. Ultra-Wideband Technology was also discussed in the New Technology Bulletin in March 2001, Vol. 1, Issue 7, before the multiband OFDM proposal was created. In fact, Time Domain's Paul Withington presented the talk “Time Modulated Ultra-Wideband” to the Federal Wireless User's Forum in May 2001. As described by Robert X. Cringely in his Aug. 8, 2002 article, “Good News!”, it was mentioned that Xtreme Spectrum had already produced a working UWB chip capable of 100 megabits per second over 10 meters, and the article further explained the idea of mesh networking, which will provide efficient network paths that allow very high data rates across the internet for remote downloading of files.
In “Ultrawideband.ca Mesh Networking Explained”, Ultrawideband.ca explains they have software that allows a user to install, on their PC, a MeshBoot disk which attempts to find internet gateways at particular Internet Protocol addresses using a DHCP client. If no gateway can be found, the software causes the users' PC to simply serve as a wireless repeater-cell. This type of operation is controlled by the software on the CD, and requires installation by the user. In future years, there are parallels that can be drawn between some of the features and functionality in the MeshBoot software for Internet use, and the capabilities that will be required to be embedded in network hardware, rather than provided on a CD for installation on PCs, in order to support massive amounts of traffic in and around homes and offices (Rather than on the world-wide web or Internet).
Repeaters are well known in the art, and they have been manufactured for decades in the cellular and PCS industries, and more recently, a company in Melbourne Fla., WiDeFi has developed WiFi repeaters for the IEEE 802.11a/b marketplace (See WiDeFi web pages describing their patent pending designs for range and bridge extension for Wireless LAN standards). Buffalo Technology announced a bridge and repeater product for IEEE 802.11g wireless LAN WiFi standard on Jun. 17, 2003 (See SmallNet Builder website page), and indicated that its repeater provides point-to-point or 6 station point-to-multi-point operation. Buffalo indicated it had security features such as WiFi Protected Access (WPA), WEP, Password protection, and MAC address association control. It uses a browser based interface for configuration, and has a 10/100 Ethernet LAN connection port, and sells for the suggested price of $149. SMC Networks introduced, on Jun. 6, 2003, its SMC2671W 2.4 GHzGHz 11 Mbps Wireless Ethernet Adapater, which provides an interface between the wired Internet backbone and the wireless LAN network. It also has wireless repeater capabilities for WLAN range extension, and has both Ad-Hoc (peer-to-peer) and Infrastructure (client to AP) operating modes, WEP encryption, WPA, MAC Address filtering, and SSID Broadcast Disable. It uses a web browser or Window-based administration software for configuration. Andrew Corporation makes classic PCS/Cellular repeaters, such as the fully integrated PROPAGATOR repeater shown on its webpage. The repeater uses standard 110 VAC power and has a single package for all signal processing components. Qualcomm has recently developed repeater technology for CDMA.